The trip, landing and expedition would be broadcast back to Earth in a reality-show type presentation.

So why not return to Earth? Lansdorp told the BBC during the seven-month trip a person would lose a lot of muscle and bone mass. The gravitational field on Mars is far weaker than Earth and after adjusting it would be physically impossible to re-adjust to Earth if you returned.

Critics of the project say they doubt humans could survive an extended stay on Mars. The director of the University of Arizona's Lunar and Planetary Laboratory Dr. Veronica Bray says unlike Earth, the atmosphere on Mars is practically a vacuum and there's little or no protection from solar winds. Scientists believe solar winds and radioactive particles from the sun stripped away most of its atmosphere millions of years ago.

At one time, it's believed Mars had a climate similar to Earth, but now it's extremely cold because the lack of atmosphere. What water is on the planet is frozen or hidden underground. Much higher levels of radiation also pose a health hazard.

Nonetheless, the Dutch company has received thousands of applications. Candidates who pass the necessary tests will be physically and psychologically "prepared" to spend the rest of their life on the planet, if the expedition actually takes place.

Another group, the U.S.-based Inspiration Mars Foundation, hopes to raise funds to send a couple to Mars and back in 2018. Founder and millionaire Dennis Tito hopes to prove humans can go to Mars and back using current technology.